WASHINGTON (AP) — The Treasury Department has imposed sanctions on virtual currency mixer Tornado Cash, which has allegedly helped to launder more than $7 billion worth of virtual currency since its creation in 2019.

Treasury's Office of Foreign Assets Control says Tornado Cash's systems were used to launder more than $96 million drawn from the June Harmony blockchain bridge theft and August Nomad crypto firm heist.

Mixing services combine various digital assets, including potentially illegally obtained funds and legitimately obtained funds, so that illegal actors can obscure the origin of stolen funds.

"Tornado Cash has repeatedly failed to impose effective controls designed to stop it from laundering funds for malicious cyber actors on a regular basis and without basic measures to address its risks," said Brian Nelson, Treasury's undersecretary for terrorism and financial intelligence.

He said the agency "will continue to aggressively pursue actions against mixers that launder virtual currency for criminals and those who assist them."

Monday's actions are the second-ever set of sanctions imposed on a digital currency blending firm.

In May, the U.S. announced sanctions against North Korean digital currency mixing firm Blender.io, accused of helping Lazarus Group, a sanctioned North Korean cyber hacking group, to carry out a $620 million digital currency heist in March.

The new sanctions also point to the growing use of digital assets to perpetuate illegal acts by state actors and individuals.

Lawmakers and administration officials have voiced concerns about the use of cryptocurrency to engage in illicit acts.

In March, President Joe Biden issued an executive order on digital assets, in part calling for federal regulators to help mitigate the illicit finance and national security risks posed by misuse of digital assets.